The BAU investigates a series of murders that appear to be connected to a killer who jumps trains and chooses his victims based on their proximity to the railway.
Giant guinea pigs are attacking cities all over the world. The boys have the key that will save everyone from the onslaught but they're stranded in the Andes Mountains.
The boys take on the challenge of building a car that will beat traffic by rising up -- and driving over it. And as an added bonus, the lift allows the vehicle to find parking like nothing else on wheels. The key to this build is a set of amazing wheels that can move in all directions without actually turning.
SAMCRO plans retaliation on a rival biker club while dealing with wounded Cameron Hayes in the clubhouse; Jax, Bobby and Opie try to end the gun debt for good.
Discontent with being raised by his octogenarian Father and depressed, middle-aged half sister, Joe searches for a more vibrant guardian.
As Election Day nears, Patrick insists on taking his relationship with Carmelita public; Ellen's brother, Chase, demands to know the truth about his sister's death; Nick and Lisa go to couples therapy; Brian Jr. goes missing.
Christine and Barb prepare for a casual, non-relationship-seeking double date with two guys they meet at a video store, but jealousy arises when only one of them gets asked out for a second date.
After recuperating from her health scare, Adrianna returns and tries to make amends with Naomi, but her ex-BFF refuses to forgive her for the betrayal. Adrianna makes a surprising connection with Navid, who helps her through her situation. Meanwhile, Annie and Ethan finally take their rapidly growing romance to a new level during the school's homecoming dance, causing Naomi to feel jealous.
A baby with AIDS has Benson and Stabler asking for assistance from Warner as they investigate the case. They are pointed in the direction of a homeopathic doctor who has an questionable ethical past and who had prescribed the baby ineffective vitamins.
With Lucas back within MI5 he reveals that the Russians interrogated him about Operation Sugar Horse, the most secret ongoing spy operation MI5 ever had. If the Russians know about it, then MI5 has a very high level mole. Harry seeks out his mentor, The Spycatcher, to help him find the mole. Ben is undercover with an Al-Qaeda cell; they are planning to bomb London and what looks like a dry run unexpectedly turns live.
San Francisco lawyer Eli Stone begins to see things, which leads him to discover a brain aneurysm. But his visions lead him to accept cases with little monetary gain but a lot of moral goodness.
Ferrari expert and master car restorer Wayne Carini gets a lead on a 1972 Ferrari Daytona Spyder for sale in Denver. Abandoned in a shed in the early '80s, the car has been painted an awful lime green and hasn't been driven for 27 years. It seems like a disaster, but Wayne has a hunch that he knows who the original owner is. With just 48 hours to put together a deal, Wayne and a friend hop aboard a private Gulfstream 450 in the middle of a blizzard and fly to Denver with the hopes of buying this rare Ferrari.
Vic closes in on Shane, Mara and their sick young son; Claudette dismantles the Strike Team; Pezuela offers Acevada "assistance" for his mayoral campaign; Rita Denton (Frances Fisher) comes on to Dutch; and Billings' ex-wife and daughter are fearful when a registered sex offender moves into their neighborhood.
An ailing man suffers from blackouts and sleepwalks, leading the team to wonder if his sleepwalking is a symptom, or how the man is becoming exposed to something else. When the man's daughter grows ill as well, the team must provide a diagnosis before both die. Meanwhile, Cuddy adopts a newborn but when the birth mother displays a rash, she has to make a decision between putting the mother or daughter at risk.
When a girl is found covered in blood and holding the murder weapon that killed her best friend, she becomes an obvious suspect, though she can't remember anything. But Jane, believing she's innocent, engineers a risky maneuver in which she must relive the terrifying events in order to spark her memory.
The team must shift their attention from a case they are working on and hand it over to Martin, after a child is reported to have been kidnapped at a mall.
Alien pods are discovered in an abandoned garage; a retirement-home resident has a deadly gift; a patient wishes to be reattached to his formerly conjoined twin; a power-company employee confronts a scientist who is stealing power to create the ultimate weapon.
Casey is in panic mode after the diary that details her unsettling romantic dreams about Truman goes missing. Believing that Derek and Edwin took it, Lizzie and Marti attempt to get the diary back by making their stepbrothers' lives miserable.